Speedfight 2 jetting

[Jackward]

Hi everyone. Ive got a 2001 peugeot speedfight 2 liquid cooled derestriced with 8 gram rollers. I was running a technigas with a 72 jet in and the spark plug was a blacky brown colour. My exhaust broke so i fitted a stage 6 pro replica and it needs jetting up this is were i am having trouble this is what ive done so far

Picture 1- This is a new spark plug with and 85 jet after a 5-6mile ride then turned off at full throttle. The bike didnt bog when i let off the throttle then went back onto it. but going down hill at about 48 if i let off and go on it will bog. ive had an 82 jet in and an 88 but i didnt use new plugs and couldnt tell any difference.

Picture 2- is with the 88 jet in. I no this would be too rich and i didnt use a new spark plug but i couldnt tell the difference between the 85 and 88 jet.

Picture 3- this is with the 85 jet without a new plug

Do you think i need to go up from and 85 jet or down? im not sure what to do thanks for any help in advance

[gavcarter]

[Jackward]

How long would you recommend i do it for mate?

[Nobby the Bastard]

[Jackward]

thanks Mr helpfull . If i could afford one i would. My familys no got alot of money and im full time at college and there not much workin going on at the moment were i work

[gavcarter]

a minute should be more than enough to get a colour on the plug

[Nobby the Bastard]

To be frank, if you are tyring to tune a modified 2 stroke without a dyno you should be happy that the fucker even works, let alone trying to optimise it.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[gavcarter]

bit of this

https://www.bmridersclub.com/images/Holed%20Piston.jpg

bit of that

https://farm6.static.flickr.com/5013/5502827159_361b9a0b44_m.jpg

few of those

https://met-tech.com/images/clip_image002_048.jpg

then he will know how far to go next time

[evoboy]

If its a 50cc speedfight, your rollers are far too heavy so it will never rev enough for you to jet it correctly.

Less than 6gram is normally a good starting point.
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Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[_Iain_]

[_Iain_]

edit. double post
____________________
Please be aware that the above post may be full of complete nonsense.
Riding: '07 KTM Duke II, Baotian BT49QT-20 Driving: '88 Volvo 340

[Jackward]

Thanks both. As it happens i do have some brand new 6 gram rollers had them in with the technigas but that didnt work well. Ill get them in asap and see how it goes

[evoboy]

The stage 6 pipes tend to be quite 'high revving' so the lighter rollers will help get the engine revving in the best range for that pipe.

It also depends how heavy you are as to what roller weight you choose.

If the plug is coming out on the blacker side of tan coloured, then i would sort out the gearbox tune before going much further with the jetting.
____________________
Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[Jackward]

Cheers. Ive got some 5.5gram and i weigh about 12 stone. They will be going in tomorrow and i will post a pic and info on when done

[Jackward]

Cheers. Ive got some 5.5gram and i weigh about 12 stone. They will be going in tomorrow and i will post a pic and info on when done

[Jackward]

Put 5.5s in and i just revs really high and seems to be unable to go past 20mph

[gavcarter]

[Jackward]

Ive never changed the spring and my friend who had it before has never changed it. All the variator and clutch have been off and cleaned a couple of days ago. Its just wierd how i put 8grams in and it will do 55 but less that 7 and it will struggle but all my mates are running about the same speeds but they all have 5gram and under rollers? Cheers

Also a wierd thing is its had the same clutch atleast 2 years and the pads still look like there brand new?

UPDATE clutch pictures

+ variator slides look worn? also snapped one

Clutch pads are smooth and shiny? sure this a bad thing

[Jackward]

Things are starting to go normal now. Got another standard variator with a malossi back plate put the 5.5s in no luck still. But put 7.5s in and huge difference straight away big difference in pulling power could even feel it pulling up past 35mph but after it got to operating temperature it seemed to drop back to like it was with 8s but the bike is running rich at the moment. Im thinking i need to try some 7grams what you think?

85 jets definetly too big as it was running a 72 jet with my technigas and theres excess oil coming out my can onto the exhaust so a 13 jet size increase is abit stupid. So im feeling that it will be safe running the 82 jet without risk of damaging the bike?

on the phone i was told it would be around 80 but start at 85 to be safe as they have not finished dynoing the exhasut so they dont know what size it could be. Also seen someone who has a leo vince zx hes running an 82 jet and these exhausts are roughly the same

[evoboy]

The contrast spring in the rear pulley is too stiff. It will of been changed to a stiffer one. You need the heavier weights to overcome the stiffness of the spring. All that does is put excess stress on the engine, rollers and belt.

If your running just a stock 50cc kit with a pipe then the standard weight spring will be fine.

Youll then find it will rev about the same as it does now, but most likely be quicker in acceleration and top speed.

With the jetting, just keep going up in jet size 1 size at a time till the engine bogs at full throttle, then go smaller by 1 size.
____________________
Suzuki GT250 x7------- Fazer 600------CB250RS------Aprilia Rally 70----- Bandit 600

APT Motorcycles

[Jackward]

Cheers i think you could be right. My springs black and the only black one i can find is 1500rpm so im guessing 1000rpm is a standard spring?

Orderd some 6.5 rollers and i can mix.them with my 7.5s to make 7 gram too. If it runs bad with the 6.5s ill know for sure its the torque.spring